Libssh2 up to 1.8.0 SSH Server integer overflow

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in Libssh2 up to 1.8.0. Impacted is an unknown function of the component SSH Server. Such manipulation leads to integer overflow. This vulnerability is traded as CVE-2019-3855. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Libssh2 up to 1.8.0. Affected by this issue is an unknown function of the component SSH Server. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. Impacted is confidentiality, integrity, and availability. CVE summarizes:

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

The bug was discovered 03/18/2019. The weakness was shared 03/21/2019 by Chris Coulson as confirmed bug report (Bugzilla). The advisory is shared for download at bugzilla.redhat.com. This vulnerability is handled as CVE-2019-3855 since 01/03/2019. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 3 days. During that time the estimated underground price was around $0-$5k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 172157 (SUSE Enterprise Linux Security Update for libssh2_org (SUSE-SU-2019:13982-1)).

Upgrading to version 1.8.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at EUVD (EUVD-2019-13469) and SecurityFocus (BID 107485†). The entries VDB-131993, VDB-131994, VDB-132105 and VDB-132210 are related to this item. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.8

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CNA Base Score: 7.5
CNA Vector (Red Hat, Inc.): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Integer overflow
CWE: CWE-190 / CWE-189
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Libssh2 1.8.1

Timelineinfo

01/03/2019 🔍
03/18/2019 +74 days 🔍
03/18/2019 +0 days 🔍
03/21/2019 +3 days 🔍
03/23/2019 +2 days 🔍
12/17/2025 +2461 days 🔍

Sourcesinfo

Advisory: RHSA-2019:0679
Researcher: Chris Coulson
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2019-3855 (🔍)
GCVE (CVE): GCVE-0-2019-3855
GCVE (VulDB): GCVE-100-132104
EUVD: 🔍
SecurityFocus: 107485 - libssh2 Multiple Security Vulnerabilities

See also: 🔍

Entryinfo

Created: 03/23/2019 09:28
Updated: 12/17/2025 23:18
Changes: 03/23/2019 09:28 (62), 05/19/2020 10:06 (5), 08/04/2023 14:21 (4), 08/04/2023 14:23 (12), 12/17/2025 23:18 (15)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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